enhancement and monitoring of nesting habitat for common

Enhancement and monitoring of nesting habitat for

Common Loons (Gavia immer) on Whatshan Lake Reservoir

Mandy Kellner and Harry van Oort

Kingbird Biological Consultants Ltd.

Revelstoke BC

250-837-0820

[email protected]

Dec 2011

Prepared for BC Hydro Fish and Wildlife Compensation Program

Kingbird Biological Consultants: Loon Habitat Enhancement 2011 i

Executive summary Common Loons (Gavia immer) are large, piscivorous birds that nest on the shoreline of lakes,

immediately adjacent to the water. At Whatshan Reservoir in southeastern British Columbia,

construction of a dam and flooding of original wetland and riparian habitats has likely led to the

reduction of suitable nesting habitat. Further affecting the productivity of loons at Whatshan, are

disturbance from human development and recreation on the reservoir, and the flooding of nests

through reservoir operations. Floating nest platforms have been used successfully to increase loon

reproductive success in other lakes and reservoirs, and could help mitigate negative impacts of reservoir

operations and encourage the loons to nest away from areas prone to human disturbance. In response

to a low rate of reproductive success documented during previous work, we installed five floating

artificial nest platforms in spring 2011. The platforms were received and installed late in the breeding

season. They were planted with local plants and anchored in protected coves, in areas known to be used

by nesting loons. There was vigorous growth of herbs on the platforms, and survival of alder and willow

seedlings and stakes. By mid-summer, platforms were vegetated enough to appear as riparian habitat,

adding diversity to the reservoir and potentially offering resting, foraging, or cover habitats to wildlife.

Loons did not nest on the floating platforms in 2011, likely due to of the late deployment of the

platforms. We monitored 5 pairs of territorial loons, 4 of which attempted to nest and 2 of which were

successful in hatching 1 chick each (2/5 pairs, 40% success). We located 5 nests in total. Of the 2

successful nests, 1 was on a natural floating platform made by a root ball mass, which has been used

both successfully and unsuccessfully in the past. The second was a late re-nest at shoreline on an island.

This nest hatched over 1 month after the first successful nest. Of the 3 unsuccessful nests, 1 was on an

old dock and likely failed due to human disturbance, 1 shoreline nest was flooded, and 1 failed to

develop, probably due to immersion of the eggs in water at full pool.

The failures of nests as a result of flooding in 2011 reinforce the potential of floating platforms to

increase reproductive success. Platforms may also help prevent late incubation and hatch dates, such as

observed in 2011. However, platforms could lead to an increase in human disturbance. To try and lower

this possibility, most platforms were placed in areas of little or no human activity, and information signs

regarding the project and loon behaviour were installed around Whatshan Lake. Small, unobtrusive

signs were also attached to platforms to identify them as nesting habitat and ask boaters to avoid the

area.

Platforms were left anchored in place for the winter in order to assess durability of the platforms and

anchoring systems. To assess the utility of these platforms as permanent habitat enhancement

structures, their post-winter condition will need to be determined. Some spring maintenance will be

required to ensure that anchor cables are snag-free and functioning correctly, and that platforms are

floating at the correct level. We also recommend low-intensity monitoring of nesting loons to

determine if loons do use the platforms in the 2012 season and how this affects reproductive success.

Kingbird Biological Consultants: Loon Habitat Enhancement 2011 ii

Keywords Common loon, Gavia immer, reservoir, nesting success, nesting habitat, artificial nesting platform,

Whatshan Lake

Kingbird Biological Consultants: Loon Habitat Enhancement 2011 iii

Table of Contents

Executive summary ........................................................................................................................................ i

Keywords ....................................................................................................................................................... ii

List of Figures ............................................................................................................................................... iv

List of Tables ................................................................................................................................................ iv

Introduction .................................................................................................................................................. 1

Study area ..................................................................................................................................................... 2

Methods ........................................................................................................................................................ 3

Platform Installation ............................................................................................................................. 3

Loon nest surveys.................................................................................................................................. 7

Data analysis and management ............................................................................................................ 7

Results ........................................................................................................................................................... 7

Timing of nest initiation and incubation ............................................................................................... 7

Nesting success ..................................................................................................................................... 7

Platform condition ................................................................................................................................ 8

Public education .................................................................................................................................. 10

Other wildlife ...................................................................................................................................... 10

Discussion.................................................................................................................................................... 10

Use of platforms .................................................................................................................................. 10

Nesting success of loons ..................................................................................................................... 10

Platforms ............................................................................................................................................. 11

Enhancement implications.......................................................................................................................... 12

Acknowledgements ..................................................................................................................................... 13

References .................................................................................................................................................. 13

Appendix 1. Loon nest information ........................................................................................................... 15

Appendix 2. Photo log of plant development on platforms ....................................................................... 17

Appendix 3. Issues and solutions for platforms and anchoring systems. ................................................... 20

Appendix 4. Public education signage installed in 2011 ............................................................................. 21

Appendix 5. Incidental observations of wildlife at Whatshan Lake, 2011 .................................................. 22

Kingbird Biological Consultants: Loon Habitat Enhancement 2011 iv

List of Figures Figure 1. Map showing the location of Whatshan Lake in south-central British Columbia. ........................ 2

Figure 2. New platform ready for being planted with vegetation. ............................................................... 4

Figure 3. Planting a new platform during installation. ................................................................................. 4

Figure 4. Location of artificial nest platforms and natural loon nests on Whatshan Lake, summer 2011. .. 5

Figure 5. Attaching anchor block to cable, showing hose for protection, quick link, and cable swage. ...... 6

Figure 6. The ½ block pulley system ............................................................................................................. 6

Figure 7. Reservoir elevation, minimum water elevation allowed under the current WUP, and initiation

dates for successful and unsuccessful loon nests at Whatshan Reservoir, 2011. ........................................ 8

Figure 8. The South End platform in July, showing herbaceous growth and new leaves on willow stakes. 9

Figure 9. Damaged area on the North End platform, Oct 13. Fibres were excavated from a hole and

strewn around. .............................................................................................................................................. 9

Figure 10.Successful nests: nest WG2 (left), which hatched a single young, with the fate of the 2nd

egg or

young unknown, and nest LG1 (right) which hatched 1 young from the single egg and was constructed

on a natural floating platform on the base of a small floating log. ............................................................ 16

Figure 11.Failed nests: nest SE1, which failed likely due to human disturbance (left), nest WG1 about to

be flooded (centre), and nest FL1 (right), which later contained 2 eggs that did not develop, perhaps due

to immersion. .............................................................................................................................................. 16

Figure 12. Flicker Lagoon (FL) platform when first planted May 28 (left) and on Oct 13 (right). ............... 17

Figure 13. Lagoon (LG) platform on May 28 ( left) and Oct 13 (right). ....................................................... 17

Figure 14. North End (NE) platform on June 6 (left) and Jul 24 (right). ...................................................... 17

Figure 15. South end (SE) platform on Jul 24 (left), with sprouting willow stakes, and on Oct 13 (right). 18

Figure 16. White Grouse (WG) platform on Jun 20 (left), showing the ramp that was later removed, and

on Oct 13 (right), with sprouting willow stakes and info sign. ................................................................... 18

Figure 17. Leaf-out on apparently dead willow stakes (left), lush herbaceous growth (centre), and a

growing alder seedling (right). .................................................................................................................... 19

Figure 18. Long roots growing down through a platform are visible in the water below. ......................... 19

List of Tables Table 1. Pros and cons of nest platforms, and particularly Floating Islands, as a habitat enhancement

measure to benefit Common Loons. .......................................................................................................... 11

Kingbird Biological Consultants: Loon Habitat Enhancement 2011 1

Introduction Common loons (Gavia immer) nest immediately next to the water’s edge, often amongst emergent

vegetation (Campbell et al 2008), and select diverse microsites such as muskrat mounds, floating or

emergent logs, bare ground, or floating bog mats, with floating mats offering the best chance of nesting

success (McIntyre and Barr 1997). On Whatshan Lake Reservoir (and elsewhere in the Columbia Basin)

much of the higher-quality nesting habitat along the lakeshore was likely lost with reservoir creation,

and was replaced largely by the steep dry banks that surround much of the reservoir at present (Utzig

and Schmidt 2011). Areas within Whatshan Lake Reservoir that appear to offer suitable nesting habitat

become flooded by rising reservoir levels each spring.

Potentially compounding the impacts from reservoir creation and operations are other factors known to

be detrimental to loon nesting success, such as the waves created by motorized recreation on the

reservoir and the shoreline development along the southern lake. Four years of data on loon

reproductive success and timing of reproduction on Whatshan Lake between 2006 and 2010 have

shown that most pairs of loons do not successfully reproduce and that reproductive rates are low (0 – 50

% of nests are successful per year) (van Oort and Kellner 2007, van Oort and Kellner 2008, Kellner and

van Oort 2009, Kellner and van Oort 2011), compared to the Canadian average of 50% or better

(Timmermans and Jones 2002). Over the 4 years of monitoring 4 or 5 loon pairs each year, 4 nests were

confirmed (and others suspected) to have failed due to rising water levels flooding nests built on shore

or on unstable floating substrates (Kellner and van Oort 2011). Other causes of nest failure were

suspected human disturbance and suspected predation.

An indirect negative impact to the productivity of loons nesting on Whatshan Lake Reservoir is that

successful nests are most commonly initiated near or after the reservoir has reached full pool, late in the

nesting season (Kellner and van Oort 2011). This results in later dates for nest initiation, compared with

other records from the West Kootenay which document nesting in early- to mid-May (Campbell et al

2008), and also results in late hatching of young, with potential consequences for juvenile recruitment.

Research in other regions has shown that loons readily use artificial floating nest platforms (Piper et al

2002, McIntyre and Barr 1997), and that reproductive success can increase when nesting platforms are

used (Piper et al 2002). In British Columbia, the use of floating nest platforms has been suggested as a

“management tool” for loon populations on reservoirs (Campbell et al 2008).

At Whatshan Lake Reservoir, the configuration of the shoreline, with secluded bays and lagoons, plus

the relatively small drawdown height of the reservoir, are conducive to enhancement with nesting

platforms. Additionally, data is available on reproductive success, timing of nesting, and causes of nest

failure prior to enhancement, to which the post-enhancement data could be compared. For this project,

we therefore proposed to enhance loon nesting habitat on Whatshan Lake by providing artificial,

floating nest platforms. The aim was to reduce nest failures due to flooding while avoiding any negative

impacts from increased predation or human disturbance to nests. We installed 5 floating nest platforms

and monitored their use and the reproductive success of all Common Loons nesting on Whatshan Lake


in 2011. The artificial platforms were developed by Floating Islands International. We also monitored the

state of the platforms throughout the summer, to document plant growth and assess suitability of this

technology for enhancement work in Whatshan and other BC reservoirs.

Study area Enhancement work and monitoring was done at 5 locations on Whatshan Lake Reservoir. Whatshan

Lake Reservoir west of Lower Arrow Lake, immediately north of Hwy 6 at the Needles ferry, and

approximately 55 km southwest of Nakusp, BC (Fig. 1).

Figure 1. Map showing the location of Whatshan Lake in south-central British Columbia.

The reservoir is approximately 17 km long with a convoluted shoreline and a number of lagoons and

islands. The reservoir supports considerable fish stocks and is valued for its recreational fishery. The

southern end of the reservoir is characterized by high levels of shoreline cottage development and is

used heavily during the summer months for motorized water sports. Water level fluctuations at the

Whatshan Lake Reservoir are controlled throughout the year by the operations of the hydroelectric


power generating plant. These operations are detailed by the Whatshan Lake Reservoir Water Use Plan

(BC Hydro 2005). In this document, it was prescribed that the water levels should be maintained at or

above: 636.5 m during the winter; 639.1 m elevation from May 15 th to June 14 th; and, 640.35 m from

June 15th to October 1st. These target water levels were developed to benefit recreational quality and

fish populations of the reservoir.

Methods

Platform Installation

Loon nesting platforms were pre-fabricated by Floating Islands West, California

(http://www.floatingislandswest.com). They are approximately 2m X 1.5m in size, and constructed with

durable non-toxic plastic mesh product that can acts as a rooting substrate for vegetation (Figure 2).

They were planted on-site with a combination of locally-sourced grass, sedge, herbaceous plants, and

shrub seedlings or stakes. Rock wool, a growing medium that supplies water and air to roots and allows

for easy root growth, was first inserted into pre-formed holes to wick water up to plants, then plants

with small root balls or bare roots were placed in the holes (Figure 3). Mats of moss and duff were used

to provide potential nesting material, and a combination of earthworm castings, moss, and soil was used

to cover any bare matrix material and provide a growing medium for plants or seeds. The entire

platform was over-seeded with a mix of herbaceous seeds commonly used to revegetate drawdown

zones in the region, and rocks and wood were added, as necessary, to achieve the desired floatation

level. Branched stakes of alder or willow, 1 – 2 m tall, were added to provide some cover from aerial

predators.

Platform installation locations were selected based on the following criteria for a site, adopted from

DeSorbo et al (2008):

1. lack of nesting success in previous years, due to water level fluctuations,

2. within the boundaries of established territories, and near old nest sites – to prevent behavioural

changes such as increases in aggression, increased intrusions into territories, or new territories

being squeezed in, as observed by Mager et al (2008),

3. protected from wind and wave action, with waves being generated by wind or power boats,

4. without extensive shoreline development, and

5. acceptable to BC Hydro and the public.


Figure 2. New platform ready for being planted with vegetation.

Figure 3. Planting a new platform during installation.

Platforms were installed between May 28 – 31, 2011 and monitored until October 13 to assess

condition, and provide maintenance if necessary. Two platforms were moved late in the summer: wave

action was greater than anticipated at one site; and we waited for a pair of nesting loons to finish

nesting at a second site, prior to making the final installation in order to minimize disturbance. Final

platform locations are shown in Figure 4.


Figure 4. Location of artificial nest platforms and natural loon nests on Whatshan Lake, summer 2011.

Two anchoring systems were used, both involving 2 anchors per platform, attached to opposite sides. In

all cases, the anchors consisted of 1 or 2 submerged concrete cinder blocks attached by plastic-coated

aluminum aircraft cable and stainless steel quick-links (Figure 5). A length of plastic garden hose was

used to protect the cable from rubbing and fraying against the anchor blocks (Figure 5). In the static –

anchor system (used on 2 platforms), both sides of the platform were connected directly to the anchor

cables, with enough slack to be gently taught at full pool elevations. On the other 3 platforms, a pulley-

system was used on the one side, in an attempt to better accommodate water level fluctuations. The

pulley-system involved running the cable from the anchor blocks up through a pulley at the platform

and down to ½ of a concrete block suspended in the water column (Figure 6). For both systems, all

cables were adjusted to allow platforms to be fully buoyant at full pool.


Figure 5. Attaching anchor block to cable, showing hose for protection, quick link, and cable swage.

Figure 6. The ½ block pulley system


Loon nest surveys

We monitored the nesting behaviour and reproductive success of Common Loons on Whatshan Lake

Reservoir from late May to late July, 2011, using the protocol of Kellner and van Oort (2011).

Monitoring was conducted, weather-permitting, using a canoe and two observers. If the weather was

not conducive to boating, monitoring occurred from shore where possible. For each of the 5 territories

previously identified on the lake (Kellner and van Oort 2011), we attempted to locate loon pairs, and

their nest sites if possible, and determine the number of eggs and fate of these nests. If loon pairs were

accompanied by young, the number, size, colour, and behaviour of young were recorded (McIntyre and

Barr 1997). When a loon or nest was located, a handheld global positioning system (Garmin Map76CSX)

was used to record its location on the reservoir.

Data analysis and management

Data from field notebooks were entered in an Excel spreadsheet after each survey. All waypoints were

downloaded and saved on computer, and projected in ArcView to check accuracy of the waypoints and

associated field notes. Data on nest locations and success and the final report are to be submitted to the

Province of BC through the Wildlife Species Inventory submission site. Data on nesting success will also

be submitted to the Canadian Lakes Loon Survey.

We examined observations to estimate dates for nest initiation, start of incubation, and hatching. To

determine the impacts of reservoir operations on loon nests, we documented the fate of all known

nests as the breeding season progressed and as the reservoir filled. To determine at what date nests

would no longer be affected by reservoir operations, we obtained data on daily maximum water levels

at Whatshan from BC Hydro and determined the date of maximum water elevation. We calculated

nesting success per year as the number of loon pairs observed with young divided by the number of

territorial loon pairs observed in spring.

Results

Timing of nest initiation and incubation

Nesting by loons was underway when the platforms were first installed in late May. Two loons were

incubating on May 28, on nests containing 1 and 2 eggs (Lagoon and South End territories, respectively,

Figure 6). Other incubation start dates were June 6 (White Grouse) and June 20 (Flicker Lagoon and

White Grouse). The June 20 nest at White Grouse was a re-nest, following the flooding of the pair’s

initial nest from June 6. Information on nest locations, dates of initiation, and fates is detailed in

Appendix 1, and nest locations are mapped in Figure 4.

Nesting success

Loons did not nest on the platforms in 2011. Using natural nests, 2 of the 5 pairs on Whatshan Lake

Reservoir successfully hatched 1 young each (40% of pairs were successful). One very small, black chick

was observed on each of June 20 (Lagoon territory) and July 24 (White Grouse territory re-nest). In total,

5 nests were located for 4 pairs, with the 5th

pair never showing obvious nesting behaviour (e.g.,


localizing around an area or nest-building). Of the 3 failed nests, 1 failure was likely due to the high level

of human disturbance at the nest site and area, and we suspect that two nests failed as a consequence

of flooding by the reservoir operation. For one of these latter nests, our confidence that the reservoir

flooded it was low; evidence to support this cause of failure was that the eggs had failed to develop, and

that the reservoir increased in elevation following nest initiation (Figure 7).

Platform condition

All 5 platforms supported excellent plant survival and growth throughout the summer (Appendix 2).

Vigorous herbaceous growth occurred from transplanted herbs and from seeds (Figure 8). Alder

seedlings survived and grew new leaves. Willow and alder stakes also sprouted new leaves throughout

the summer.

Date

1/Apr 1/May 1/Jun 1/Jul 1/Aug 1/Sep 1/Oct

Re

se

rvoir

ele

va

tio

n (

m)

636

637

638

639

640

641

642

Reservoir elevation

WUP minimum water level

Initiation date of successful nests

Initiation date of failed nests

Figure 7. Reservoir elevation, minimum water elevation allowed under the current WUP, and initiation dates for successful

and unsuccessful loon nests at Whatshan Reservoir, 2011.


Figure 8. The South End platform in July, showing herbaceous growth and new leaves on willow stakes.

Wave action on the newly-planted platforms was clearly detrimental on small portions of two platforms

(North End and White Grouse). These affected sides were washed of soil, duff, and seeds, although

plants remained in pre-made holes in the matrix. All affected areas were re-covered and re-seeded, and

burlap was used in 1 case to provide extra cover and retain soil. Platforms affected by wave action were

relocated.

Physical damage was found on one platform (North End) in October (Figure 9). This platform was

partially torn apart, with a hole dug in the matrix and the debris scattered around. No evidence was

found to identify the culprit species but potential suspects included muskrats and otters.

Figure 9. Damaged area on the North End platform, Oct 13. Fibres were excavated from a hole and strewn around.

Anchoring systems appeared intact after the summer, with the exception of wear on one of the cables

on the North End platform, where the cable was attached to the quick-link on the platform. This

platform was moved to a more sheltered area and should be closely inspected in spring. The concrete


blocks used as anchors appeared to be sufficient to keep platforms from drifting or being moved by

wave action during summer months. The ½ block pulley system was working well to absorb slack in

anchor lines when viewed in October, when reservoir levels were 640.5 m, well above winter minimums

of 636.5 m. Appendix 3 details some issues that arose with the platforms in. Platforms were left in place

for winter 2011/2012.

Public education

A sign describing the project was developed and installed at the south end of the lake (Appendix 4). This

is where the majority of development, fishing activity, and power boat mooring occurs. Small signs were

affixed to each platform to identify them as loon nesting platforms. Generic loon information signs

(Loon Alert, supplied by the Canadian Lakes Loon Survey) were posted at the 2 public boat launches at

forest service campsites at the north end of the lake. Informal discussions with lake users, regarding

loons, loon behaviour, nesting habitat, and human impacts, occurred opportunistically throughout the

summer.

Other wildlife

In July, spotted sandpipers (Actitis macularius) were seen foraging on the South platform. A list of other

incidental wildlife observations is included as Appendix 5.

Discussion

Use of platforms

The lack of use by nesting loons was not surprising. Platforms were installed when 2 out of the 5 pairs

were already incubating, due to delays in procuring the Floating Islands. Platforms should be installed

before nesting begins, and ideally soon after the lake becomes ice free (NALF 2005, DeSorbo et al 2008).

Upon installation in late May 2011, the platforms did not resemble natural nesting habitat and were

clearly new structures introduced into the loon territories. We expect that chances of loons using the

platforms will be much greater in 2012; the loons will be familiar with the platforms, now well-covered

by vegetation. It is normal for the use of platforms to increase in the years after installation (Piper et al

2002, DeSorbo et al 2007).

Nesting success of loons

Loons had relatively high nesting success at Whatshan Lake in 2011, with 40% of the loon pairs raising 1

young. Success rates in previous years have ranged from 0 % in 2006 (van Oort and Kellner 2006) to 50

% in 2008, or an average of 30% from 2008 to 2010 (Kellner and van Oort 2011). Flooding of nests

continues to lead to late initiation dates for re-nesting attempts. For example, the flooding of an early

nest at White Grouse led to the successful re-nest around Jun 20, and the sighting of a single very small

young in late July. This chick was hatched over 1 month later than the other successful nest this season.

As discussed in Kellner and van Oort (2011), delayed nesting could have implications for size at fall

migration, juvenile survival, and future reproduction (Newton and Marquiss 1984, Hochachka 1990,

Naef-Daenzer et al. 2001).


Platforms

One platform (South End) was installed in an area with considerable shoreline development and human

activity, and where there was a history of nest failure due to high levels of human disturbance. Although

platforms are not generally recommended for this type of site (DeSorbo et al 2008), loons continue to

nest in the high use area without success, and so we installed a platform in this territory in hopes of

luring the pair away from the old dock that has been used as a nest platform in previous years. This dock

provides a relatively quiet site in May when the loons select it for nesting, but receives high use by

humans in June and July. For example, we have observed people fishing off the dock when the loons

were nesting and mooring powerboats adjacent to the nest site. The new nest platform is approximately

200m from the old dock, but is behind the protective log boom that guards the Whatshan Dam, and will

hopefully provide a nest site with fewer disturbances, if selected by the loons. Floating buoys or signs

may be useful to further reduce human activity in the area if the platform is used by loons in the future.

Growth of the plants on the platforms, and their appearance at the end of the summer in 2011, was very

promising. The durability of the platforms throughout the winter is unknown, and may certainly detract

from the potential of this technology as a habitat enhancement tool at Whatshan Lake Reservoir.

Ideally, the platforms will withstand winter conditions on the lake and thus require little maintenance.

Standard protocol for cedar log rafts is to remove them from the water each fall and re-install each

spring, so the logs do not become waterlogged (NALF 2005, DeSorbo et al 2008). Water logging is not an

issue for the synthetic Floating Islands, and remaining in the water should contribute to the

development of plant communities on the rafts. However, removal of rafts protects them and the

anchoring systems from the potentially destructive action of ice. These, and other, pros and cons are

detailed in Table 1.

Table 1. Pros and cons of nest platforms, and particularly Floating Islands, as a habitat enhancement measure to benefit

Common Loons.

Pro/con Issue

� Floating nest platforms provide nesting habitat that should be safe from flooding and are

known to appeal to loons in other areas.

� Islands are naturally buoyant and will not become waterlogged, so they do not need to be

removed from the water to dry, possibly resulting in lower maintenance than cedar

platforms.

� Pre-formed islands are light and easy to work with, for installation, planting, and anchoring by

2 people. Installation can be done by zodiac or canoe.

� The matrix seems excellent at supporting plant growth and the platforms quickly develop a

natural appearance with lush growth. The presence of vegetated islands adds complexity to

the reservoir habitat even if not used by loons.


� Platforms could negatively impact reproductive success if their use results in greater human

disturbance or predation.

� Platforms could negatively impact reproductive success if anchors become tangled and

platforms cannot float properly.

� Some research has indicated negative impacts on loons after platforms were installed, due to

increased aggressive behaviours between loons (Mager et al 2008).

� Uncertainty about winter-hardiness or long-term durability at this point in time.

� Relative to cedar platforms, the Floating Island platforms pose larger potential to become

garbage if they break from moorings or are destroyed by ice, because they are synthetic.

Enhancement implications The vegetated islands clearly add to the diversity of habitats available at Whatshan Lake, and potentially

benefit many wildlife species through providing foraging habitat, resting spots, or cover. However, the

appeal of nest platforms to loons remains uncertain, due to the late deployment of the platforms in

2011. If the platforms begin to be used by loons, platforms may offer a solution to impacts from both

habitat loss and reservoir operations. However, concerns and potential negative impacts remain.

Specifically, anchoring systems and floatation of the platforms must be checked in the spring to ensure

that the platforms do not initially appeal to loons as nesting habitat and then lead to nest failure due to

flooding from poor floatation or snagged anchor lines. Other concerns regarding platforms include

increased aggression between loons, and resulting reductions in survival and productivity (Mager et al

2008). These potential negative impacts of platforms should be considered; however, while ensuring

that the platforms function properly should be within the scope of most monitoring programs,

monitoring intrusions or aggression towards chicks or adults is likely not. Fortunately, it is thought that

these negative impacts may be short term (Mager et al 2008), and that platforms should increase

productivity of loons in the long term (McIntyre and Mathesion 1977, Piper et al 2002).

As a result, we recommend follow-up work to include:

1. a site visit early spring to ensure that anchoring systems have not been destroyed by winter

conditions and are still anchored and functioning properly,

2. monitoring of use of platforms or natural nests by loons in early May and June, and

3. monitoring hatching success of loons in July.

Targets would include ensuring that platforms function correctly, and determining if platforms led to an

increase in nesting success, and if possible, determining causes of nest failures.


Acknowledgements Financial, logistical, and technical support, as well as GIS work, was contributed by the Fish and Wildlife

Compensation Program- Columbia. We are especially grateful to Irene Manley who contributed greatly

to the project through initiating the use of Floating Islands and providing enthusiasm, support, and

hours of work planting and installing platforms. We thank Laddie Flock and his team at Floating Islands

West http://www.floatingislandswest.com/ for providing the Loon islands used in this project.

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45pp.


Appendix 1. Loon nest information

Table A-1. Locations, descriptions, and fates of loon nests on Whatshan Lake, 2011.

Date Territory Nest ID UTM_X UTM_Y Description # eggs Fate

28-May-11 Lagoon LG-1 421748 5535048

On natural floating platform of log / root ball with

sod. Same site as previous 2 years (2009, 2010).

Mud and grass nest.

1 Hatched

1 young 20-Jun

28-May-11 South End SE-1 419825 5530257 On old dock. Mud and grass nest. Same site as

2010. 2

Failed by

20-Jun. Human

disturbance.

06-Jun-11 White

Grouse WG-1 421324 5539432

East side of island, mossy nest below overhanging

alder. 1 Failed by 11-Jun.

Flooded.

20-Jun-11 White

Grouse WG-2 421263 5539464

East side of island, nest of mud and vegetation on

shore. 20 m from platform. 2 Hatched

1 young 24-Jul.

20-Jun-11 Flicker FL-1 421909 5536252 Flattened grass/sedge at waterline on peninsula.

20m from platform. 2

Failed, observed

13-Oct. Suspect

flooded.


Figure 10.Successful nests: nest WG2 (left), which hatched a single young, with the fate of the 2nd

egg or young unknown, and nest LG1 (right) which hatched 1 young from

the single egg and was constructed on a natural floating platform on the base of a small floating log.

Figure 11.Failed nests: nest SE1, which failed likely due to human disturbance (left), nest WG1 about to be flooded (centre), and nest FL1 (right), which later contained 2 eggs

that did not develop, perhaps due to immersion.


Appendix 2. Photo log of plant development on platforms

Figure 12. Flicker Lagoon (FL) platform when first planted May 28 (left) and on Oct 13 (right).

Figure 13. Lagoon (LG) platform on May 28 ( left) and Oct 13 (right).

Figure 14. North End (NE) platform on June 6 (left) and Jul 24 (right).


Figure 15. South end (SE) platform on Jul 24 (left), with sprouting willow stakes, and on Oct 13 (right).

Figure 16. White Grouse (WG) platform on Jun 20 (left), showing the ramp that was later removed, and on Oct 13 (right),

with sprouting willow stakes and info sign.


Figure 17. Leaf-out on apparently dead willow stakes (left), lush herbaceous growth (centre), and a growing alder seedling

(right).

Figure 18. Long roots growing down through a platform are visible in the water below.


Appendix 3. Issues and solutions for platforms and anchoring systems.

Issue Solution

Anchor cable showed wear in one instance. Galvanized chain may be preferable to attach a

stationary anchor; however, the pulley system

requires cable. Protecting platforms from wave action

will help reduce wear on cables.

The anchoring systems used have a risk of snagging

on the stumps on the reservoir bottom, leading to

platforms not floating correctly and loon nests

getting inundated as the reservoir fills.

Pulley systems reduce slack in the system and are

recommended. Platforms and cables should be

checked in the spring to ensure they are floating

correctly. Attempt to locate platforms in stump-free

areas.

The design of the Floating Islands needs refining. Specifically:

1) the square, high edge on the initial platforms may

be difficult for loons to access unless weighted down

with rocks and logs, as done in 2011, and

2) the ‘ramps’ for chicks to access the platform were

poorly designed – the painted plywood was bubbling

and peeling, and the attachment method with the

supplied yellow polypropylene rope was poor quality

and visually disturbing when trying to be unobtrusive.

The platforms should simply have gently sloping edges

all around.

Excavation in to a platform by some unknown

animal occurred in the late summer or fall.

Identification and deterring of the culprit is necessary.

Wave action interfered with plant establishment. Platforms should be monitored soon after installation

to ensure plants are growing and not being overly

disturbed, and to determine if platforms need to be

relocated.


Appendix 4. Public education signage installed in 2011


Appendix 5. Incidental observations of wildlife at Whatshan Lake, 2011 Date Location Species Total Male Female Young Comments

28-May-11 Loongoon Osprey 1

30-May-11 S end Osprey 1 overhead.

30-May-11 powerline on

whatshanrd Osprey 1

on nest on

transmission

pole

30-May-11 s end Spotted

Sandpiper 4

nesting around

dam?

30-May-11 Flicker Spotted

Sandpiper 2

06-Jun-11 N lake Mallard 1 1

06-Jun-11 N lake Gull sp. 1

06-Jun-11 powerline on

whatshanrd Osprey 1 on nest

11-Jun-11 Arrow park

ferry Canada Goose 10 6 pretty big kids!

11-Jun-11 White Grouse Spotted

Sandpiper 1 on island

20-Jun-11 Loongoon Osprey 1

24-Jul-11 Ritchie campsite Common

Merganser 3 1 2

female and 2

young

24-Jul-11 Ritchie campsite Osprey 1 on nest S of

campsite

24-Jul-11 Ritchie campsite cedar waxwings many

24-Jul-11 N shore Deer 1

mule or white

tails, seen from a

distance on

muddy shore

24-Jul-11 N shore Great Blue Heron 1

24-Jul-11 N shore Kingfisher 1

24-Jul-11 N shore cedar waxwings many

24-Jul-11 White Grouse Vaux's swift 1

25-Jul-11 powerline on

whatshanrd Osprey 1

on nest on

powerline tower

25-Jul-11 Whatshan Dam Spotted

Sandpiper 2

on platform and

boom

25-Jul-11 Whatshan Dam Solitary Sandpiper 2 resting on boom

25-Jul-11 Whatshan Dam Barn Swallows 3

drinking/foraging

at seepage area

on dam

25-Jul-11 Narrows Common

Merganser 12 1


13-Oct-11 N end Mallard 6

13-Oct-11 N end Hooded

merganser 1

13-Oct-11 Narrows Kingfisher 1

enhancement and monitoring of nesting habitat for common

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